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. 1997 Sep 15;17(18):7079–7102. doi: 10.1523/JNEUROSCI.17-18-07079.1997

Fig. 7.

Fig. 7.

A surface-based coordinate system for the left hemisphere [u, v]L-SB and right hemisphere [u, v]R-SB of the Visible Man, displayed on a map of cortical geography. The origin corresponds to the ventral tip of the central sulcus, and grid lines are spaced at 20 map-mm on each map. The horizontal (u) axis extends from −253 to +170 map-mm for the left hemisphere and from −254 to +171 map-mm for the right hemisphere. The vertical (v) axis extends from −145 to +188 map-mm for the left hemisphere and from −134 to +174 for the right hemisphere. The bottom panels show lateral and medial views of the hemisphere, with the surface-based coordinate system wrapped up into 3-D space. The mean separation between adjacent resampled nodes in 3-D was 0.95 mm for the left hemisphere and 0.96 mm for the right hemisphere. This signifies an average linear expansion of 5% on the flat maps. Any point in the volume that lies above or below the surface can be represented in 3-D surface-based coordinates, using its distance from the surface in 3-D as one coordinate (w) and the nearest point on the surface for the other two coordinates ([u, v, w]R-SB or [u, v, w]L-SB, depending on the hemisphere). To determine the correspondence of the surface-based coordinates of major geographical landmarks, the centers of gravity (white dots) were determined for nine sulci: the central, postcentral, superior temporal, collateral, olfactory, fronto-orbital, and superior rostral sulci, plus dorsal and ventral halves of the calcarine sulcus (see Results and Table 2).